package org.nobody.mallb2c.mallcart.interceptor;

/**
 * @author 3489309323@qq.com
 * @create 2020-09-19-19:07
 */

import org.apache.commons.lang.StringUtils;
import org.nobody.common.constant.AuthServerConstant;
import org.nobody.common.constant.CartConstant;
import org.nobody.common.vo.MemberRespVo;
import org.nobody.mallb2c.mallcart.to.UserInfoTo;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.util.UUID;

/**
 * 在执行目标方法之前, 判断用户的登录状态。
 *
 * 并封装传递给controller目标请求
 */
public class CartInterceptor implements HandlerInterceptor {
  public static ThreadLocal<UserInfoTo> threadLocal = new ThreadLocal<>();

  /**
   * 会在目标方法执行之前执行
   * @param request
   * @param response
   * @param handler
   * @return
   */
  @Override
  public boolean preHandle(
    HttpServletRequest request,
    HttpServletResponse response,
    Object handler
  ) {
    UserInfoTo userInfoTo = new UserInfoTo();
    HttpSession session = request.getSession();
    MemberRespVo member = (MemberRespVo) session.getAttribute(AuthServerConstant.LOGIN_USER);

    if (member!= null) { //用户已登录
      userInfoTo.setUserId(member.getId());
    }

    Cookie[] cookies = request.getCookies();
    if (cookies != null && cookies.length > 0) {
      for (Cookie cookie : cookies) {
        String name = cookie.getName();
        if (name.equals(CartConstant.TEMP_USER_COOKIE_NAME)) {
          userInfoTo.setUserKey(cookie.getValue());
          userInfoTo.setTempUser(true); //本次获取到了临时用户信息
        }
      }
    }

    //如果没有临时用户 一定分配一个临时用户
    if (StringUtils.isEmpty(userInfoTo.getUserKey())) {
      String uuid = UUID.randomUUID().toString();
      userInfoTo.setUserKey(uuid);
    }

    //目标方法执行之前,先放点东西进去
    threadLocal.set(userInfoTo);
    return true;
  }

  /**
   * 业务执行之后执行: 分配临时用户,让浏览器保存
   * @param request
   * @param response
   * @param handler
   * @param modelAndView
   * @throws Exception
   */
  @Override
  public void postHandle(
    HttpServletRequest request,
    HttpServletResponse response,
    Object handler,
    ModelAndView modelAndView
  ) throws Exception {
    UserInfoTo userInfoTo = threadLocal.get();

    if(!userInfoTo.isTempUser()/*←← 这个意思是本次没有获取到临时购物车(没有设置临时购物车的cookie)*/){
      Cookie cookie = new Cookie(CartConstant.TEMP_USER_COOKIE_NAME, userInfoTo.getUserKey());
      cookie.setDomain("mall.com");
      cookie.setMaxAge(CartConstant.TEMP_USER_COOKIE_TIMEOUT);
      response.addCookie(cookie);
    }
  }
}
